Determination of the Content of Promoters in Magnetite and Wustite Phases in the Fused Iron Catalyst

Taking advantage of differences in etching rates of crystallographic phases, forming an oxidized form of the fused iron catalyst, a content of promoters in main phases, magnetite and wustite, was determined. A calcium oxide content in magnetite and wustite was 0.54 wt% and 3.59 wt%, respectively. Aluminum oxide was found in the magnetite phase, and its content was 4.5 wt%. The third promoter, potassium oxide, was almost completely located outside these phases. XRD and ICP-OES instrumental methods were used in the investigations.

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Determination of the iron oxide content in bauxite: comparing ICP-OES with UV–VIS and volumetric analysis

Chemical Papers ◽

10.1007/s11696-020-01305-z ◽

2020 ◽

Vol 75 (1) ◽

pp. 389-396

Author(s):

Gordana Ostojić ◽

Dragica Lazić ◽

Saša Zeljković

Keyword(s):

Iron Oxide ◽

Volumetric Analysis ◽

Oxide Content ◽

Iron Oxide Content ◽

Icp Oes

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The activity of fused-iron catalyst doped with lithium oxide for ammonia synthesis

Polish Journal of Chemical Technology ◽

10.1515/pjct-2016-0032 ◽

2016 ◽

Vol 18 (2) ◽

pp. 78-83 ◽

Cited By ~ 2

Author(s):

Roman Jedrzejewski ◽

Zofia Lendzion-Bieluń ◽

Walerian Arabczyk

Keyword(s):

Solid Solution ◽

Active Sites ◽

Ammonia Synthesis ◽

Iron Catalyst ◽

Lithium Oxide ◽

Potassium Oxide ◽

Catalyst Precursor ◽

Two Phases ◽

Full Reduction ◽

Fused Iron Catalyst

Abstract The iron catalyst precursor promoted with Al2O3, CaO, and Li2O was obtained applying the fusing method. Lithium oxide forms two phases in this iron catalyst: a chemical compound with iron oxide (Li2Fe3O4) and a solid solution with magnetite. The catalyst promoted with lithium oxide was not fully reduced at 773 K, while the catalyst containing potassium was easily reducible at the same conditions. After reduction at 873 K the activity of the catalyst promoted with lithium oxide was 41% higher per surface than the activity of the catalyst promoted with potassium oxide. The concentration of free active sites on the surface of the catalyst containing lithium oxide after full reduction was greater than the concentration of free active sites on the surface of the catalyst promoted with potassium oxide.

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Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

Nuklearmedizin ◽

10.1055/s-0038-1632257 ◽

2000 ◽

Vol 39 (05) ◽

pp. 121-126 ◽

Cited By ~ 1

Author(s):

R. Werz ◽

P. Reuland

Keyword(s):

Bone Growth ◽

Region Of Interest ◽

Tracer Uptake ◽

Optimal Time ◽

Mandibular Bone ◽

The Third ◽

Mandibular Asymmetry ◽

Bone Scans ◽

Epiphyseal Plates

Summary Aim of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Methods: Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of nongrowth dependant differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Results: Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. Conclusion: No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

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THE FACTORS OF CAREER SELF-DETERMINATION OF STUDENTS OF HIGHER EDUCATION INSTITUTIONS

Baltic Journal of Career Education and Management ◽

10.33225/bjcem/19.7.9 ◽

2019 ◽

Vol 7 (1) ◽

pp. 9-20

Author(s):

Inna Yeung

Keyword(s):

Higher Education ◽

Higher Education Institutions ◽

Well Being ◽

Young Person ◽

Self Determination ◽

Full Time ◽

Actual Problem ◽

The Third ◽

The Right

Choice of profession is a social phenomenon that every person has to face in life. Numerous studies convince us that not only the well-being of a person depends on the chosen work, but also his attitude to himself and life in general, therefore, the right and timely professional choice is very important. Research about factors of career self-determination of students of higher education institutions in Ukraine shows that self-determination is an important factor in the socialization of young person, and the factors that determine students' career choices become an actual problem of nowadays. The present study involved full-time and part-time students of Institute of Philology and Mass Communications of Open International University of Human Development "Ukraine" in order to examine the factors of career self-determination of students of higher education institutions (N=189). Diagnostic factors of career self-determination of students studying in the third and fourth year were carried out using the author's questionnaire. Processing of obtained data was carried out using the Excel 2010 program; factorial and comparative analysis were applied. Results of the study showed that initial stage of career self-determination falls down on the third and fourth studying year at the university, when an image of future career and career orientations begin to form. At the same time, the content of career self-determination in this period is contradictory and uncertain, therefore, the implementation of pedagogical support of this process among students is effective.

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